To those familiar with instant adhesives, it's no surprise that their vapors can expose fingerprints with the white residue caused by monomer "blooming". In fact, efforts to reduce this undesirable behavior date from the early days of cyanoacrylate technology.
However, it was left until much later to discover that this same process could be turned to the noble task of apprehending criminals through fingerprint identification. In 1978 the Tokyo Metropolitan Police are reported to have hosted a demonstration of cyanoacrylate fuming for development of fingerprints by criminologists of the Japanese National Police Agency. In May of 1979, Detective Inspector N. Edmunds and L. Wood of Northamptonshire (England) Police are reported to have observed that fingerprints were developed when they repaired a black plastic developing tank with Loctite Super Glue.TM.. Within a month, they reported their findings to a regional police conference.
Constable Paul Bourdon of the North Bay Ontario Police Force was an early practitioner of the method and invented a fuming system which generates vapor in one chamber and pumps it into another which contains the evidence under investigation. His system has been patented in the U.S. and Canada (U.S. Pat. No. 4,297,383, incorporated herein by reference).
Frank Kendall of the U.S. Bureau of Alcohol, Tobacco and Firearms, developed an improvement in the method which uses cotton treated sodium hydroxide to accelerate the generation of vapors. A description of this technique is given in Identification News, June 1982, page 3.
The use of heat to accelerate generation of cyanoacrylate vapors for fingerprint development use has also been reported. Identification News, January 1983, page 9, and May 1983, page 10.
The cyanoacrylate vapor technique has become an accepted method for fingerprint development. In several cases, identifications have been made on evidence for which no previous methods had been workable. Recently, evidence provided by this method has been accepted in a Kansas court leading to criminal conviction. Abele, Identification News, February 1983, page 12.
Recognized benefits of using cyanoacrylate monomers to develope fingerprints which have been discovered to date are as follows:
(a) Development of latent prints on objects where other methods have failed;
(b) development of prints on difficult surfaces such as polyethylene bags or electrical tapes;
(c) print images produced are easier to handle than powder-dusted prints which may blow away;
(d) large enclosed areas, such as automobile interiors can be fumed for prints.
The significant benefits of the cyanoacrylate fingerprint development technique, however, have been accompanied by other notable disadvantages. These disadvantages include the instant bonding of cyanoacrylate adhesives to skin and clothing when contacted by evidence technicians. Also, the typical low viscosity cyanoacrylate adhesive used in the prior techniques is easily spilled or dripped. This not only contributes to inadvertent bonding of clothes and skin but can also result in damage to the evidence. Initially, without acceleration of vapor generation, it has been reported that full development of a print takes at least about five hours and can take as long as 90 days.
With acceleration of vapor generation, other disadvantages have been identified as follows: